Fundamentals of Systems Engineering
Prof. Olivier L. de Weck
Session 12
Future of Systems Engineering
1
Status quo approach for managing complexity in SE
CostOptimization
Power Data & Control Thermal Mgmt
SWaPOptimization
SWaPOptimization
System FunctionalSpecification
. . .
. . .
SubsystemDesign
ComponentDesign
SystemLayout
Verification & Validation
ComponentTesting
SubsystemTesting
SWaP = Size, Weight, and Power
Undesirable interactions (thermal, vibrations, EMI)
Desirable interactions (data, power, forces & torques)
V&V = Verification & Validation
System decomposed based on arbitrary cleavage lines . . .
Conventional V&V techniques do not scale to highly complex or adaptable systems–with large or infinite numbers of possible states/configurations
SWaP used as a proxy metric for cost, and dis-incentivizes abstraction in design
Unmodeled and undesired interactions lead to emergent behaviors during integration
. . . and detailed design occurs within these functional stovepipes
MIL-STD-499A (1969) systems engineering process: as employed today
Re-Design
Resulting architecturesare fragile point designs
3
Change Request Generation Patterns
Change Requests Written per Month
0
300
600
900
1200
1500
Nu
mb
er
Wri
tte
n
[Eckert, Clarkson 2004]
Discovered new change pattern: “late ripple”
component design
subsystem design
system integration and test
bug fixes
major milestones or management changes
1 5 9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
Month
© Olivier de Weck, December 2015, 4
(Common Semantic Domai
P (AP , GP) Ca± Cb±
Composition Rules
C1(A1; G1) C3(A3; G3)
C4(A4; G4)
Actor
Library
CP (AP , GP) Ca± Cb±
Composition Rules
C1(A1; G1)
2( 2 2)
C3(A3; G3)
C4(A4; G4)
Actor
Library
DARPA META Approach to 5x acceleration of SE
6
Requirements Definition
Manufacturing
Deployment
Abstraction‐Layer Design Layer N
C =
Layer 2
=
C A ; G Layer 1
CP (AP , GP) = Ca ± Cb ±
Composition Rules
C1(A1; G1)
C2(A2; G2)
C3(A3; G3)
C4(A4; G4)
Actor
Library
…
Requirements Definition
Manufacturing
Deployment
System Validation ‐ Confirmation
Concept Design
Preliminary Design
Detailed Design
System Integration
System Validation
Uncertainty
C n, A i i1
n
kaijk k1
4
j1
n
i1
n
E A
‐ Structure, organization, dynamics
• Adaptability
• Complexity
• Performance
• 1st Cost
Metrics
T3
META Product‐Development Design Flow
Conventional Product‐Development Design Flow e.g., MIL‐STD‐499
Design Time: T Design Time: 0.2T T1
T2
T1
10T2
0.1T3
T4 0.2T4
‐ Switching cost for alternative architectures
n)Meta-Language (Common Semantic Domain)
Design‐Space Exploration Layer N
Layer 2
Layer 1
Interactions
A bitstream-programmable, “foundry-style” factory
Fuels & Tribology
Harness Buildup
Electronics Fabrication Automated
Harness Loom
total space for GCV-scale capability Need not be geographically co-located Custom components in-sourced to iFAB network Unmodified COTS components out-sourced
Assumptions: • 40k-60k ft2
Paint & Finish • Drill & fill • Wire bundles • • Robotics •
Additive/Subtractive •Manufacturing
Welding Sheet Metal Fabrication
Composites Autoclave
Tape Laying
CNC Brake
Anodizing
CNC Tube
Test Set
Laser Cutter 3D Printer
6-Axis Laser Robots Fuel Cell
Sintering Paint Welding Assembly Booth Robots Automated Swaging
Storage and CNCPress Retrieval CMM
Tank
AGVs Articulating CMMBender
Machine Instructions (STEP-NC, OpenPDK)
Dynamometer
Logistics
Tube Bending
iFAB Foundry Configuration
Product Meta-Representation
7
Hydraulics & Pneumatics QA / QC
This image is in the public domain.
Vensim Model of META (5x) Process Complexity RDT&E (NRE) Cost META flag (on/off)
Levels of Measure Abstraction
Schedule Pressure
Key META-related Certificate of features shown in red Model Completion Library
Changede Weck O.L., “Feasibility of a 5x Speedup in System Development due to META Design”, Paper DETC2012-70791, ASME 2012 International Design Engineering Technical Conferences (IDETC) and Management Computers and Information in Engineering Conference (CIE) Chicago, Illinois, August 12-15, 2012
© ASME. All rights reserved. This content is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/help/faq-fair-use/. 8
Spending Rate
6 M
4.5 M
3 M
1.5 M
0
0 12 24 36 48 60 72 84 96 108 120
Time (Month)
Spending Rate : META - enabled
Spending Rate : Realistic (with changes)
Spending Rate : Idealistic (no changes)
Benchmark Case Results (3,000
requirements )
Simulation Case Schedule to complete NRE $ to complete
Idealistic Project 42.25 months $27.9M
Realistic Project w/changes 70 months $51.9M
META-enabled project 15.75 months $31.5M
META-enabled
Idealistic Project Realistic project (no changes) with changes
Simulation Assumptions: All: Schedule Pressure = 1.5 META: 3-layers of abstraction (CB=9) META: C2M2L library coverage: 50% META: Novelty: 50% META: C2M2L library integrity: 80% Problems caught early: 70%
Key Result:
META speedup factor = 70/16=4.4
Confirmed that META speedup of 5x is possible but cost reduction is only 1.5 x !
9
Validation: 777 Electric Power System (EPS)
Project Parameters from Hamilton Sundstrand:
5 Years– Feb 1990 (project work authorized) – Jan 1995 (final qualification test complete)
Source control drawing was completed in 1993 This is the complete equipment spec.
Number of customer requirements: ~1,500
Number of Change Request: ~300
Total number of major components: 33 2 Integrated Drive Generators (IDG); 1 auxiliary generator (APU
driven); 3 Generator Control Units; 1 Bus Power Control Unit; 24 Current Transformers; 2 Quick attach/detach Units
Ratio of systems people working CDR to people working Qualification test was 1:1.5
Approach: 1. Approximately simulate B777 EPS Program execution
2. Simulate META version of B777 EPS and see impact
11
Comparsion B777 - Design and Integration, Validation and Completion
400 Specifications/Month
80 Specifications/Month
400 Requirements/Month
400 Requirements/Month
1
1
200 Specifications/Month
40 Specifications/Month
200 Requirements/Month
200 Requirements/Month
0.5
0.5
0 Specifications/Month
0 Specifications/Month
0 Requirements/Month
0 Requirements/Month
0
0
0 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
Time (Month)
Design and Integration : B777-META Specifications/Month
Design and Integration : B777-actual Specifications/Month
Validation : B777-META Requirements/Month
Validation : B777-actual Requirements/Month
Certificate of Completion : B777-META
Certificate of Completion : B777-actual
Comparison of B777 EPS Program (actual vs. META)
Completion Times: Actual: 60.75 months META: 16 months (predicted)
B777 EPS - actual
B777 EPS- META
Rework “mountain”
Requirements Defined
2,000
1,500
1,000
500
0
0 30 60 90 120
Time (Month)
Req
uir
emen
ts
Requirements Defined : B777-actualRequirements Defined : B777-META
~ 1,500 requirements
Cumulative Changes
400
200
0
0 36 72 108
Time (Month)Cumulative Changes : B777-METACumulative Changes : B777-actual
~300 vs. 100 changes
12
Summary META (5x) Model
We are continuing to quantify the schedule and cost impact of the proposed META Design Flow based on a sophisticated Vensim System Dynamics Model:
Speedup factor of 4-5 x seems feasible
Cost improvement is only about 1.5x (w/o cost to build and maintain C2M2L) META
will be much faster but not much cheaper !
Most important META Design Flow Tool Chain factors are (in order)
META Factor Rank Schedule Impact for 5x NRE $ Cost Impact
1. Most important Schedule Pressure Catch problems early
2. Layers of Abstraction C2M2L Library Coverage
3. C2M2L Library Coverage Schedule Pressure
4. Less important Catch Problems early C2M2L Library Integrity
B777 Electric Power System (EPS) design project was simulated and compared actual (1990-1995) vs. predicted outcome had META been available
B777 EPS might have been developed in 16 months (vs. 60) with META
13
What is the current state of SE? In 2010 Dr. Mike Griffin wrote a controversial article “How do we fix Systems Engineering?”:
Organization of characteristics of an “elegant design” Current state of the art in Systems Engineering research and educationand strength of academia-industry interactions
“ … lacking quantitative means and effective analytical methods to deal with the various attributes of design elegance, the development of successful complex systems is today largely dependent upon the intuitive skills of good system engineers.”
“Academic researchers and research teams are rarely, if ever, exposed to the actual practice of system engineering as it occurs on a major development program. Similarly, few if any successful practicing system engineers … make a transition to academia.”
This image is in the public domain.
Griffin M.D., “HOW DO WE FIX SYSTEM ENGINEERING?”, IAC-10.D1.5.4, 61st
International Astronautical Congress, Prague, Czech Republic, 27 September – 1 October 2010
14
Characteristics of an “Elegant Design”
According to Dr. Griffin
Workability (system produces the anticipated behavior, the expected output)
Robustness (system should not produce radical departures from its expected behavior in response to small changes)
Efficiency (produces the desired result for what is thought to be a lesser expenditure of resources than competing alternatives)
Predictability (accomplishes its intended purposes while minimizing unintended actions, side effects, and consequences)
According to Dr. de Weck
Functional Compliance (performs the functions we desire at or above the expected level of performance)
Simple Architecture (structural arrangement of the physical parts of form with only essential complexity)
Minimal Lifecycle Cost (including design effort, manufacturing cost, capital expenditures, operating expenses)
Superior Lifecycle Properties (robustness, safety, flexibility to change, maintainability, sustainability ….)
The main job of the systems engineer is to ensure that these properties are achieved and balanced
15
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Cumulative Number of Journal Articles published about each Illity
Epoch of Great Inventions Epoch of Complex Systems Epoch of Engineering Systems
Safety
Quality
Reliability
Flexibility
Robustness
Durability
Scalability
Adaptability
Usability Extensibility Evolvability
Resilience
Sustainability
Recyclability
Interoperability
Maintainability
Importance of Illities over Time
Source: Compendex and Inspec, analysis by O. de Weck, July 2010
16
Relationships amongst the Illities
Easy to make, test and use
Works well with others
Holds up well over time
Can change it if needed
Doesn’t fail and cause harm
Source: Google keyword 2-tupel correlation analysis, July 2010
17
Trends in SE: “Utopia” in 2035 We design systems with only essential complexity and they don’t fail unexpectedly “accidents” may not be preventable altogether but they may be predictable and humans can
get out of harms way
The Technical, Process and Social Layers of the system are co-designed and in harmony with each other
All system designs are essentially “elegant” and tradeoffs between lifecycle properties are made deliberately Value maximizing sustainable designs are the norm, not the exception
Projects don’t overrun their budgets because rework is eliminated oriterations are included in realistic plans that are accepted by all
There is a “Nobel Prize” awarded for Systems Engineering or Systems Science
The 1st, 2nd, 3rd .. Law of systems science and engineering is well established and widely accepted (similar to thermodynamics)
18
SE Vision 2025 Available online at
http://www.incose.org/AboutSE/sevision
19
Final Words
Thank you for your attention this semester !
Consider submitting a manuscript to the INCOSE Wiley Journal Systems Engineering
http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1520-6858
© Olivier de Weck, December 2015 20
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